There's a significant spread of quality among new tubes manufactured in different factories using different machinery and materials.

Click to expand...

You are right. But I experienced JJs, EH, Boogies etc. to be quite consistent in quality marked under each brand. (JJs mostly good, EH often disapointing among others.)
There where significant differences among each one brand`s production, though. Especially in the late nineties, where supply of tubes ran really short and only some obscure chinese tubes could be bought and selected by the wholesalers.

It'll sound different but you won't know if it's better til you Try. Of course, after putting all that time and money into It, you would be let down if it's not a significant improvement, so you will probably convince yourself you like the change. Or you can just not do the change and be happy with your sound and the money in your wallet.

It'll sound different but you won't know if it's better til you Try. Of course, after putting all that time and money into It, you would be let down if it's not a significant improvement, so you will probably convince yourself you like the change. Or you can just not do the change and be happy with your sound and the money in your wallet.

Click to expand...

**************************
That's a very reasonable comment Henry, I take it to heart and appreciate it. On the other hand, I'm a very pragmatic person...if I don't like the sound, I won't like it, no amount of money spent will color my opinion. Good is good, not so good is not so good...$$$ have no effect on my ears. Fortunately, the cost is minimal for me in this case, the biggest downside is the aggravation of putting JJ's back in and getting them biased etc. if I don't like them.

The 68 Custom Deluxe Reverb I purchased a while back remains my favourite amplifier. I've kept the original 6V6 Groove (JJ) tubes and have no issues with them. There are no rattles and the amplifier sounds really good. I've changed the pre-amp tubes but that's it.
A fellow I know and trust has some NOS 6V6's I can get at a "real deal" and he's offered to bias the amplifier properly for them as well.
I have to admit I'm intrigued based on things I've heard about good NOS tubes. I don't want to fix something that's not broke and I know I can always reverse things.
My question, have you had any personal experience, good, bad or meh, using NOS tubes? Besides tone, I'm concerned about the reliability. From what I've read if they are good NOS tubes they are more rugged than new tubes...but I can't say I know that to be a fact and I use this amplifier a lot at varying volumes.

Any comments would be appreciated.

Click to expand...

I've never owned NOS tubes myself but have played amps of buddies who had them inserted.
Sounded good and never heard anything bad about em.

But as with all tubes and all amps there is no right or wrong and no ultimate best.
It's 100% personal preference and some tubes suit some amps better than others.
It's all about what tones you are trying to achieve in what specific amp.
No one tube brand or type is the answer in all situations for all users.

I'm more interested in the characteristics of each individual tube than who made it.
I'm clear about what amp tone outcomes I want and I choose tubes specifically to deliver it.
So provided it's a good quality durable tube and delivers the features I want I don't care who made it or where it came from.

And by choice I've never had the same brand of tube in every position.
All JJ pre-amp & power tubes, for example, in every position in 1 amp maybe what you prefer but may not be my preference, or the next guys either, in THAT amp.
A high gain JJ pre-amp tube in position 2 might be perfect for me in a Mesa but no good for you in a Fender or Vox.
And I don't want low gain noisy tubes anywhere near my amps but they maybe be perfect for a country picker with an Fender Twin.

I've tried lots of different tubes made easier because the Mesa Boogie amps I own don't require re-biasing when you change tubes.
You just insert and play on Mesa amps.

It's also worth mentioning, that some shops also sell pre-selected tubes, which comes in handy, if you want lowest noise levels.

Click to expand...

That a very valid point Chris. Just as an aside, I've purchased so called matched sets of tubes (new ones) and there has been as much as 8mV difference in them. That said, I've also bought matched tubes that were almost bang on.

This is just my thoughts about using 'old' tubes from my half century experience and this is not comparing the advantages/disadvantages of newer stock tubes and their audio characteristics. This is just about age.

When a tube lays around for half a century doing nothing, age can take a toll. Such things as a slight leakage in the envelope allowing air molecules in to make it 'gassy'. Other things I've noticed that daily temperature changes causing expansion/contraction of the elements and their internal 'welding' process can cause them to loosen rendering the tube microphonic or intermittent at worst. Also sometimes the internal elements can sag and bow due to father time/temperature causing shorts & noise etc.

I've used NOS stuff quite a lot and it's a crap-shoot. You may or may not get lucky. On my last amp build, I used NOS 12AU7's and withing a couple months noticed all the above happening to some degree. Am I against NOS tubes, heavens NO! I'm an old ham radio operator and we are well known for being 'cheap' and using whatever is at hand. But as someone stated earlier in these posts, if you are a 'gigging' musician I'd spring for the best tubes you can find. It's kinda like an old fellow pilot once told me. "When you are flying at 15,000 feet over the mountains... you want the best spark plugs money can buy".

This is just my thoughts about using 'old' tubes from my half century experience and this is not comparing the advantages/disadvantages of newer stock tubes and their audio characteristics. This is just about age.

When a tube lays around for half a century doing nothing, age can take a toll. Such things as a slight leakage in the envelope allowing air molecules in to make it 'gassy'. Other things I've noticed that daily temperature changes causing expansion/contraction of the elements and their internal 'welding' process can cause them to loosen rendering the tube microphonic or intermittent at worst. Also sometimes the internal elements can sag and bow due to father time/temperature causing shorts & noise etc.

I've used NOS stuff quite a lot and it's a crap-shoot. You may or may not get lucky. On my last amp build, I used NOS 12AU7's and withing a couple months noticed all the above happening to some degree. Am I against NOS tubes, heavens NO! I'm an old ham radio operator and we are well known for being 'cheap' and using whatever is at hand. But as someone stated earlier in these posts, if you are a 'gigging' musician I'd spring for the best tubes you can find. It's kinda like an old fellow pilot once told me. "When you are flying at 15,000 feet over the mountains... you want the best spark plugs money can buy".

Click to expand...

***********************
IMHO, you've summed this up really well and my sentiments are very similar, actually pretty much identical. The price I can get these tubes for, as well as the NOS hype, is what has/had me considering them. But at the end of the day reliability is a HUGE factor for me. I would not tolerate terrible sound/tone for the sake of reliability but I think NNS (New New Stock) tubes such as JJ's (and others) can provide both reliability and good tone.

***********************
IMHO, you've summed this up really well and my sentiments are very similar, actually pretty much identical. The price I can get these tubes for, as well as the NOS hype, is what has/had me considering them. But at the end of the day reliability is a HUGE factor for me. I would not tolerate terrible sound/tone for the sake of reliability but I think NNS (New New Stock) tubes such as JJ's (and others) can provide both reliability and good tone.

Click to expand...

So right Robbie. I think nostalgia is the most motivating factor here. And as I remember back in the 60's when I first started servicing electronics that tubes were no more reliable (and perhaps even less reliable) than the new stock is today. Tubes by their very nature were always problematic, even straight out of their new shiny box. You could always count on a few bad apples in the barrel.

Other than guitar amps (for their sound), the best thing to happen in electronics was the Transistor.

In my opinion new tubes are more uniform and constant in quality.
But: The quality is a lot inferior to vintage ones when we are talking GE/Siemens/Gold Lion/Philipps/AEG 12ax7, EL34 or KT66 (thats the type of tubes I usually work with).
Every time I have the opportunity to buy these type of NOS tubes for a fair price I pull the trigger.

There is a point that cannot be discussed-away: There are very few poweramp tubes that are built for really high voltages. E.g.: Old HiWatts need very high voltages at the tube that nearly all modern EL34 cannot deliver. You need old stock tubes to have a reliable performance.

One thing to remember is as time goes by the best of the NOS tubes are starting to go away.
In America for instance tubes haven't been made here since the early 1980s - that's 35+ years ago.
So now we're getting to the bottom of the barrel and finding high quality NOS tubes is just going to get harder to do.
No doubt some of the best tubes in history were made in the USA - when they started phasing out making tubes here more and more of them were made in other countries and lots of those tubes were considered to be inferior to the ones made in the USA.
Recently I've found hundreds of places that are selling bulks of so called NOS tubes.
Many have been repackaged and are used tubes - most of them are borderline bad tubes that should have been thrown away 25 years ago.
So you really have to be careful when you buy tubes that are marked as NOS.
Really good NOS tubes can really sound great in a good guitar amp but finding good "old" tubes these days is getting harder to do.
I've had a good stock pile of NOS tubes that I bought over the years - many of them back in the 80s & 90s when you could find them really cheap.
Now the supply is getting low and I've been using some of the new tubes such as JJ and I have to admit some of them sound really good.
I don't think they last as long as the old USA made tubes by GE, RCA, etc. but the prices are pretty reasonable.

There's a significant spread of quality among new tubes manufactured in different factories using different machinery and materials.

The same is equally true of old tubes.

Just because it's old, doesn't mean it's good. Which is the opposite of what I tell my missus.

Click to expand...

I'm with you 100% on this. I remember watching TV repairmen in the '70s and they would often try several tubes before they found one that worked well. Not all vintage tubes were good tubes. Perhaps more to the point, the tubes that remained in their boxes for the last 40-50 years might well be the tubes that techs rejected back in the day.

Don't get me wrong, there are some great NOS vintage tubes out there, but just because a tube is NOS vi Tate does not automatically make it a great tube.

A few years ago, I installed a quad of new production 6L6s in my TRRI and was astounded by the balance of the set. They were beautifully matched and once properly biased made that amp sound absolutely fantastic.

The 68 Custom Deluxe Reverb I purchased a while back remains my favourite amplifier. I've kept the original 6V6 Groove (JJ) tubes and have no issues with them. There are no rattles and the amplifier sounds really good. I've changed the pre-amp tubes but that's it.
A fellow I know and trust has some NOS 6V6's I can get at a "real deal" and he's offered to bias the amplifier properly for them as well.
I have to admit I'm intrigued based on things I've heard about good NOS tubes. I don't want to fix something that's not broke and I know I can always reverse things.
My question, have you had any personal experience, good, bad or meh, using NOS tubes? Besides tone, I'm concerned about the reliability. From what I've read if they are good NOS tubes they are more rugged than new tubes...but I can't say I know that to be a fact and I use this amplifier a lot at varying volumes.

Any comments would be appreciated.

Click to expand...

I'll be curious as to how this turns out. I also have a '68 CDR and like the sound of the Custom channel with its Bassman-like tone stack. However, I've noticed that it's a bit "crunchy" on the low notes of late. Normally, I make a few changes to any production amp, swap a few tubes, etc. but this CDR had some teething problems along the way and I didn't want to muddy the waters until they were resolved. (It turned out that the reverb cables were the source of the problem.). Now that it's ok on that account, I need to start by biasing the power tubes, then possibly substitute a 12AY7 in V1, which improves clean headroom.

While on that subject, I will mention that I wasn't happy with the early breakup of this amp and ended up adding a resistor in parallel with the negative feedback resistor, which brought the clean headroom into line with what I would expect from a DRRI. Overall, the amp sounds good, but I must say that the road was a bit rocky, with strange phantom noises coming from the OEM reverb cables, which must have been from the lowest bidder.